Tablets, capsules, caplets and many other types of devices have been used for oral delivery of active agents. These forms are relatively easy to manufacture and convenient for use in the hospital or other institutional settings or at home. Many different types of active agents have been incorporated into such dosage forms--ranging from analgesics to antibiotics to hormones.
There are patients that, because of age or infirmity, have difficulty swallowing solid oral dosage forms. According to Kikendall et al., Digestive Diseases and Sciences 28:2(1983), there were 221 cases documented between 1970-1982 of tablet and capsule induced oesophageal injury. The most commonly implicated drugs were tetracycline (108 cases), emepromium bromide (36 cases), potassium chloride (16 cases) and ferrous salts (12 cases).
In view of the above, there exists a need for oral dosage forms where swallowing of a large solid system is avoided that are easy to use and manufacture.
U.S. Pat. No. 2,436,505 to DuRall describes a pill douser for administering medicines in liquid form or in pills or tablets. The device has a bowl at the top for containing the medicine and a tube that can be submerged in a liquid held in a drinking glass. The liquid is drawn upward for administering the liquid and any pill or tablet present in the bowl.
U.S. Pat. No. 2,867,536 to Mead et al. describes an improved drinking straw where a soluble flavoring material is contained within an annular space contained within an inner and an outer tube. The inner tube has a bore through which liquid can be drawn. During use, the upper and lower caps are removed, the flavoring material emptied into the liquid and the flavored liquid drawn up through the inner tube and into the mouth.
U.S. Pat. No. 3,610,483 to Visconti describes a dispensing device for liquid medication that is formed in the shape of a straw. A predetermined dose of liquid medication is loaded into the straw which is then capped at both ends until the medication is dispensed when a patient removes the caps and sucks air into the device.
A variety of other oral delivery systems have been described. These include a medicated pacifier (U.S. Pat. No. 5,123,915 to Miller et al.) and a lollipop type device for a solid medicament (U.S. Pat. No. 5,223,259 to Lackney). None of these devices or the devices described previously provide for the delivery of a solid medicament into the oral cavity as a bolus dose, while avoiding the difficulties inherent in swallowing a solid system such as a tablet or a capsule or the shelf-life problems encountered when a medicine is dissolved or dispersed in a fluid, preferably an aqueous liquid.